Defect Engineering of MoS₂ Nanosheets by Heavy-Ion Irradiation for Hydrogen Evolution

Molybdenum disulfide (MoS₂), a very promising nonprecious catalyst with high hydrogen evolution reaction (HER) catalytic activity, has been extensively studied for its excellent properties. Nonmetal doping and defects can effectively improve the electrocatalytic activity of MoS₂ electrocatalysts, but a lack of systematic studies on nonmetal doping and defect engineering hinders further design and improvement of the MoS₂ electrocatalysts. Herein, a novel strategy is proposed to improve the HER performance of MoS₂ via heavy-ion irradiation. Theoretical calculations show that fluorine (F), as a doping element, exhibits an excellent HER performance of MoS₂. Doping and defect engineering are combined by irradiating MoS₂ using an F^- ion beam with controllable fluence to verify whether F^- ions can effectively regulate the electrical structure of MoS₂ and contribute to its HER efficiency. This work provides a strong theoretical basis and experimental support for the rational design of the MoS₂ electrocatalysts and expands the understanding of the optimization of the electrocatalytic activity of other catalysts.